1939 BMW R66 Technical Analysis & Specification Breakdown
Engineered by BMW for the allround motorcycle segment, the 1939 BMW R66 relies on a 596 cc (36.4 cu in) air-cooled two cylinder boxer, four-stroke powerplant. In factory specification, peak output is rated at 30.1 HP (21.9 kW) at 5,300 rpm, transferring power to the rear wheel through a 4-speed gearbox and shaft drive (cardan) final drive. With a specific output of 50.5 HP per liter, the engine character is prioritizing low-RPM tractability, mechanical longevity and relaxed throttle response over peak redline numbers.
On the scales, the R66 measures 187 kg (412 lbs) wet (curb), translating to a power-to-weight ratio of 0.16 HP/kg (6.21 kg per horsepower). Rider ergonomics and chassis geometry center around a 1,400 mm (55.1 in) wheelbase engineered for quick, flickable steering geometry. The 14-liter (3.7 US gal) fuel tank supports practical everyday commuting and weekend road stints, while factory top speed is listed at 145 km/h (90 mph).
Within MotoLibrary's BMW archive, this model family spans 4 indexed model years from 1938 to 1941, allowing buyers to track year-over-year changes in emissions tuning, weight and equipment.
Use this page to compare this motorcycle by its real specifications, not only by model name. Focus on the details that affect fit, comfort, handling, range and ownership.
Power
Compare engine output with similar motorcycles if acceleration, highway use or two-up riding matters.
Fuel Capacity
Fuel capacity helps estimate touring range and how often you may need to stop.
Brakes
Brake setup is worth comparing if you ride in traffic, mountains or with a passenger.
Suspension
Suspension details can matter for comfort, road feel and long-distance riding.
Transmission
Transmission and final drive affect maintenance, smoothness and everyday usability.
